Marcus Brauchli is stepping down as Washington Post executive editor and will be replaced by Martin Baron, the longtime Boston Globe editor, the paper announced on Tuesday.

Brauchli has been the Washington Post's chief editor since the middle of 2008, but the paper has struggled with declining readership and revenues. Brauchli has frequently been at odds with publisher Katharine Weymouth, the granddaughter of legendary Post publisher Katharine Graham, over issues including the newsroom's annual budget.

“Marcus has contributed immeasurably in the more than four years he has been at the helm of this newsroom,” said Weymouth in a prepared statement. She noted that he was the first executive editor of the Post to oversee both its print and online operations.

“Under his leadership, we have become one newsroom publishing on multiple platforms. We have become known for our ability to create innovative digital products that allow our readers to engage in new ways with some of the best journalism in the world.”

Under Baron, the Globe has pursued an aggressive digital strategy, including a two-tier website model with free content and a separate subscription site. It has been slow to attract subscribers. The Globe has won many awards under Baron's leadership, and he is considered a well-loved figure in the newsroom with a measured leadership style.

In a farewell memo to the staff on Tuesday, Baron wrote: "The fiercely hard-working staffs of Boston.com and BostonGlobe.com produce two of the most vibrant news and community websites in the country. Each is distinctive in character, each is built on a different model, and both are known for their infectious innovative fervor."

Globe Publisher Christopher Mayer praised Baron's tenure -- during which the New York Times Company-owned paper won six Pulitzers, most recently for art criticism in 2011 -- calling him a "staunch advocate" of accountability journalism and the First Amendment.

"We wish him well and, in the coming weeks, we'll be celebrating his leadership and his many accomplishments. We'll also begin the process of finding his successor," Mayer wrote in a memo to the newsroom staff. "During this time of transition, I'm grateful that the Globe has a committed staff and a deep tradition of quality journalism to carry us forward."

Brauchli issued this statement: “I am enormously proud of what we have accomplished here, and honored to have worked among so many brilliant journalists,” Brauchli said. “There is no finer newsroom.”

The Post won four Pulitzer prizes during Brauchli’s tenure and was a finalist for eight others. It also won a variety of other awards including a George Polk and a Peabody award.